Yep, thats what I did. Some have complained that with the cap off of the rad, that coolant sprays everywhere. I haven't experienced that, but to avoid it, you could just use the resevoir, which has the pressure cap on it anyways.
I've also seen the claim that running with either cap off will allow the air to escape, as Disallow mentioned to you in his response. I think the front of the truck raised on ramps or a hill should accomplish about the same thing.
dawgn86 wrote:sounds good...
seems you fill the system back up just to the top of the radiator, let the engine run, maybe squeeze the top rad hose some?..top off fluid as required?